I was looking to use arduino to do a calibration rig, which can be used in lab. The scheme is to use a mass flow controller which takes analog input of 0-5 V or 4-20 mA for a predetermined flow (depends on span). I want to do 3 point calibration, i.e communicate with the MFC to set 3 different flows sequentially, wait at each flow values and record the readings from a different flowmwter that streams data out on RS485 serial comp port.
Then I wanted to log the values and do a usual line correlation and record the slope/coefficients of that line and use it for calibration.
Is this feasible?
Could anyone please recommend the correct kit and I can procure and try it.
The scheme is to use a mass flow controller which takes analog input of 0-5 V or 4-20 mA
Most of the Arduinos aren't capable of that. They can only put out PWM. You'd need external smoothing circuitry or a DAC. A few of the Arduinos have a DAC built in. Look at the different specifications on the product pages and you should be able to see which ones.
Based on the description I have no idea what you're really trying to do, nor the role of the Arduino in this. So based on the very limited and ambiguous description, can't answer your question.
It seems pretty simple to me, although there’s a lot more information required to actually build the device.
0-5V: Yes, but as Delta said, you need to convert the Arduino’s PWM output to a ‘proper’ analog signal. You may also investigate using a digital potentiometer for this.
RS485: Yes, but requires an RS485 converter chip. There should be a zillion available at your favorite auction site. Or go to one of the major Arduino retailers (Sparkfun, Adafruit or whaterver is in your country) to get one with some example code and support.
Log the values: Yes, but where is this being logged? To a PC? An SD card?
Use it for calibration: Once again, Yes, but where does this data go? PC? To the RS485 device? Display on an LCD screen?
You may also need some way of controlling this: does it plug into a PC for Serial control or does it have an LCD screen and a few buttons?